Alternate Test Procedures to Perform Clean Water Act Monitoring in EPA's Pacific Southwest (Region 9)

When performing Clean Water Act (CWA) monitoring for National Pollutant Discharge Elimination System (NPDES) compliance, only approved analytical methods identified in 40 CFR Part 136 may be used to analyze for regulated constituents.

Parties interested in modifying one of these approved methods or seeking to use a new method not in Part 136, must apply to use an alternate test procedure (ATP) in the Region in which the discharging facility is located. Applications are submitted to the Region upon concurrence by the State representative responsible for assisting in NPDES permitting. Contact the following individuals if interested in applying for an alternate test procedure:

• Arizona: Isaac Robert (roberti@azdhs.gov)
• California: qualityassurance@waterboards.ca.gov
• Hawaii: Alec Wong (alec.wong@doh.hawaii.gov)
• Nevada: Don Lafara (dlafara@ndep.nv.gov)

Once received by the Region, applications are reviewed in accordance with procedures set forth in 40 CFR Part 136.5.

Updates to 40 CFR Part 136

CWA Analysis and Sampling Procedures, Final Methods Update Rule (MUR), Effective July 17, 2021.

Rule Summary: EPA finalized specific changes to analytical test procedures that are used by industries and municipalities to analyze the chemical, physical, and biological components of wastewater and other environmental samples that are required by regulations under the Clean Water Act. The changes include:

• Revised EPA methods;
• new or revised methods published by voluntary consensus standard bodies, such as ASTM International and the Standard Methods Committee;
• new and updated methods developed by the U.S. Geological Survey;
• methods reviewed under the Alternate Test Procedures (ATP) program; and
• minor changes to quality assurance and quality control within individual methods.

Access further information on the final MUR: Methods Update Rule - 2021 on EPA’s Clean Water Act Analytical Methods website. The website includes a Current and Recent Actions section with a Draft Methods Update Rule for 2022.

EPA Region 9 highlights that 40 CFR Part 136.3(e), Table II, Required Containers, Preservation Techniques, and Holding Times take precedence over those specified in the method.